Digital recording devices (e.g., DVRs) allow users to record media programs and to play back the media programs at times that are convenient for the users. More specifically, in a typical use scenario, a user identifies a program to be recorded from an electronic program guide (EPG). The DVR device then records the identified program at its scheduled presentation date and time. The DVR commonly records the program in its local store. At a later time, the user can activate the program, at which time the DVR plays the program from its local store.
In actual practice, the EPG data contained in the EPG guide for a program may not exactly coincide with the actual presentation times of the program. For instance, the EPG guide may indicate that a program begins at 8:00 PM and ends at 10:00 PM, but the source which supplies the program may start the program at a time slightly prior to 8:00 PM, or at a time slightly after 8:00 PM. Similarly, the source may potentially end the program at a time slightly prior to 10:00 PM, or at a time slightly after 10:00 PM. Typically these offset times are short, e.g., a few minutes, but these times can also be longer (e.g., in the case of sporting events that last longer than scheduled).
DVR devices are known to account for variation in presentation times by “padding” the starting and ending times of recorded programs. Consider the scenario shown in FIG. 1. As indicated there, EPG data indicates that a program 102 is scheduled to air from 8:00 PM to 10:00 PM. However, to account for the fact that this program 102 may potentially start slightly earlier than 8:00 PM or run slightly later than 10:00 PM, the DVR device can start recording the program 102 at a padded starting time 106, and stop recording the program 102 at a padded ending time 108. In operation, the DVR device will begin playing the program at the padded starting time 106, and will continue playing the program until the padded ending time 108 (unless, of course, the user stops the program 102 before then).
In many (and perhaps most) instances, however, the program may actually start at the scheduled starting time and terminate at the scheduled ending time. These times correspond to the actual starting time 110 and the actual ending time 112. In this scenario, when the user activates the program, the user will be presented with a terminal portion of a program 114 which precedes the program 102 on this channel. And if the user watches all of the recorded content, the user will eventually advance to a program 116 which follows the program 102.
The above-described kind of DVR behavior is disadvantageous for at least three reasons. First, the user may be displeased and/or confused to see the ending part of program 114 when the user activates the program 102. If the user understands why he or she is being presented with the program 114, the user can quickly advance forward in the recorded content to find the actual starting time 110, e.g., by activating a fast forward playback mode. Nevertheless, this operation may be cumbersome, especially if the user is required to frequently perform this operation. Second, the user may also be displeased to see the end of the program 114 because this might spoil the user's enjoyment of the program 114 (that is, if the user has also recorded this program 114 and intends to watch it in its entirety). Third, recording the program 102 such that it begins at the padded starting time 106 and ends at the padded ending time 108 is not efficient, as the DVR is consuming storage space to store superfluous content. For instance, for a 30 minute program, recording a five minute padding at the start of the program and at the end of the program increases the disk consumption for that recording by 33%.
For at least the above-identified exemplary reasons, there is a need for more efficient strategies for recording and playing back media information, as well as other kinds of information.